The two streams meet at a confluence. It takes many tributary streams to form a river. A river grows larger as it collects water from more tributaries. Streams usually form rivers in the higher elevations of mountains and hills. The areas of depression between hills or mountains are known as valleys.
The world's fastest production single piston engine aircraft produced in Great Britain, deployed from 1945 to 1953. Heavily Modified Sea Fury aircraft can be seen today as air racers. Heinkel He-162 562 mph. Arguably the fastest WW II jet fighter.
The 800mph Gulfstream G650 - fastest civil aircraft ever. March 18, 2008 Since the 1960s, the Gulfstream jet has been synonymous with the fastest, ultra luxury business travel regardless of cost â only 1600 have ever been made but now, the company is raising the bar with a new ultra-large cabin G650 due in 2012.